22q11 deletion syndrome is considered one of the most common chromosomal deletions
associated with birth defects and leads to a wide range of health problems, from heart defects to behavioral disorders.
Pathogenic copy number changes smaller than approximately 5-10 Mb are not detectable; however, recent advances in chromosomal microarray (CMA) [2a] analysis now allow the detection of chromosomal deletions
and duplications at much higher resolutions (down to only a few kilobases, depending on the microarray), producing a higher diagnostic yield.
Recurrent chromosomal deletions
and duplications are observed in leukemia patients as unbalanced structural chromosomal abnormalities.
Genetic alterations of the PTEN gene at the level of mutations or chromosomal deletions
are frequently found in high-grade gliomas (Table 1).
The investigators performed a genome-wide analysis of large, rare chromosomal deletions
and duplications known as copy number variants (CNVs) in 366 children with ADHD and 1,047 controls.
Chromosomal microarray analysis is similar to a karyotype, but can find much smaller chromosomal deletions
It has been used to identify signaling and metabolic pathways associated with tumor progression, as well as to detect submicroscopic chromosomal deletions
and duplications in patients with mental retardation and other disabilities.
Researchers have learned that if chromosomal deletions
or other genetic alterations rob a cell of the function of a tumor suppressor gene, that cell can ignore the strict regulations on cell growth and division that the body ordinarily imposes.
That year, they and four other parents started Chromosome Deletion Outreach, a matching group for all conditions caused by chromosomal deletions
, additions and inversions.